Various biochemical parameters were investigated in the gerbil cerebral cortex both during and after occlusion of the common carotid artery. Ischemia produced large changes in the energy metabolites, cyclic nucleotides and certain putative neurotransmitters. There is an initial dramatic change in both energy metabolites and cyclic nucleotides after which the levels remain essentially constant. Recovery from the ischemic insult was marked by an apparent rapid restoration of energy metabolites. The results on the cyclic nucleotides and neurotransmitters seem to indicate that the recovery process is more than a mere reversal of the ischemic-induced events. The cyclic AMP fluctuations during ischemia and recovery were also duplicated in gerbil brain slices. Using in situ fixation, the effects of ischemia were also evaluated in deeper regions of the brain, including the caudate-putamen, thalamus and hypothalamus. Studies on short-term anoxia and recovery were performed and the effects were qualitatively similar to those for ischemia.